1. Field of the Invention
The present invention relates generally to computer programs and, particularly, to computer systems used to navigate virtual environments.
2. Related Art
The most common method of presenting a virtual tour of a real, physical environment is film or videotape. While such a presentation offers high visual accuracy, the progress of the tour is generally limited to a single, static route chosen by the photographer or editor. In other words, the observer of the tour has none of the choices usually available to someone who is physically in the environment: choices such as turning one way or the other at an intersection, skipping uninteresting paths, or proceeding directly to a favorite location. The observer""s interaction with the environment is limited to commands such as start, stop, fast forward or reverse. A further limitation of this approach is that the observer generally has no other context than the image, itself. That is, the limited field of view makes it difficult for the observer to orient him/herself in a complex environment.
For tours of virtual environments, computer systems are commonly used to render images from models representing the virtual environments. As opposed to videotaped presentations, such systems can be highly interactive since the images are rendered in real time. There is, however, a tradeoff between cost and visual accuracy. Computer systems capable of rendering very high-resolution images in real time are prohibitively expensive, while more affordable systems produce inferior quality images.
The present invention relates to a computer system which allows interactive navigation and exploration of spatial environments, both real and virtual. The computer system employs a data architecture comprising a network of nodes connected by branches. Each node in the network represents an intersection in the real environment that allows a user of the computer system to select which path to follow. Likewise, each branch in the network represents a path connecting physical intersections in the real environment.
The network is constructed directly from a map of the target environment. Navigation data such as image frame sequences, intersections between paths, and other related information are associated with the elements of the network. This establishes a direct relationship between locations in the environment and the data which represent them. From such an organization, the user may tour the environment, viewing the image sequences associated with each path and choosing among intersecting paths at will.
In addition to navigating through the environment, the user may also access auxiliary information that is related to particular points of interest. This auxiliary information can be of varying forms: video, audio, still images, etc. Such information is linked to a point of interest through the associated network element. By associating this information with the virtual environment, the computer system of the present invention is able to provide the observer with an enhanced view of the real environment represented by the virtual environment.